Knightmare, the 80s and 90s TV show that put kids through gruelling fantasy challenges while wearing a bucket on their head, is making a return. A special one-off episode is being filmed as part of YouTube's Geek Week, from 4 to 10 August.

It will see the return of dungeon master Treguard of Dunshelm (Hugo Myatt) who, instead of small children, will guide a series of celebrities through the CGI generated Knightmare Castle.

The show is filmed using blue-screen techniques, with the main participant unable to see any more than the floor under a large, iconic helmet. All of the effects are placed by computer in real time and the competitors' team-mates will have to guide their wards through the puzzles by viewing a remote monitor.

Old episodes of the British kids' show have been re-run most recently by Challenge TV, but this is the first time new material will have been shot in almost 20 years.

Comedian Isy Suttie from Peep Show will be joined by Harry Potter star Jessie Cave as contestants. There will also be home-grown YouTube stars involved, in order to celebrate the rise of the online medium in creating its own viral personalities.

Former Pocket-lint contributor Susi Weaser (@susiweaser) is currently working on the Knightmare remake and has been posting pictures and comments on Twitter from the set. "I've seen a massive screen. It is blue. I've seen the life force. I'm going to try on the helmet. Could this be the best day of my life?," she wrote.

Geek Week will also feature a host of other content, including a celebration of Doctor Who.